Fixed markdown wrong formatting table on pub.dev

Author: Guldem

README.md

@@ -27,6 +27,7 @@ When using `ParameterizedSource.csv` the library tries to parse the values to `i
 This parsing can be escaped by wrapping in the values in `'` or `"`.
 
 For example: 
+
 |Input | Output|
 |------|-------|
 |`'banana, 4, apple'`|`'banana'`, `4`, `'apple'`|